Methods and apparatus are provided for projecting light carrying a data
image. The apparatus comprises a first layer having regions of
electrically alterable variable light transmittance adapted to form the
data image, and a hollow cavity backlight having a light exiting surface
coupled to the first layer and adapted to provide light to the first
layer through the light exiting surface from one or more light emitters
some of which point in a principal direction other than at right angles
to the light exiting surface. In a preferred embodiment, LEDs are used as
the light emitters and are preferably mounted on one or more printed
circuit boards or other support tilted at non-zero angles with respect to
the light exiting surface.